Conventionally, indoor units having a function to remove dust adhering to an air filter are known as indoor units of air conditioners for air conditioning a room. For example, Patent Document 1 discloses an indoor unit for performing an automatic cleaning operation of automatically cleaning an air filter. This indoor unit determines whether to perform the automatic cleaning operation based on the accumulated operation time of the indoor unit. When the accumulated operation time of the indoor unit reaches a predetermined value, maintenance information is displayed on a main body display portion in order to notify the user of the need to remove dust from a dust box for storing dust removed from the air filter.